Neither my boyfriend or I have ever been bit, and we have had our ball python for three years. His father has, but he was so scared around it, he would flinch and panic. Then he tried to grab her at her face. That was a strike waiting to happen.

The more calm you are, the less likely you are to get bit. The snake is frightened, but if you are calm, he will calm down..

Imagine you are locked up and there is a big big tiger there with you. You don't know if it's going to attack you or not, but now you can see the tiger is very nervous and agitated, flinching back, making sudden movements.. WOAH Now, that is scary, and you might get defensive if that thing came close to you acting like that. That's how the snake feels!
Imagine the tiger is calm and just relaxing there with you. You'll still be nervous, but I doubt you'd do anything to attack the clearly calm animal. And eventually you might grow accustomed to it's presence.

Now it's not a perfect analogy, but it makes sense to me. Try to be calm and you won't make your snake nervous.

Snakes generally won't bite unless they have a good reason, of course sometimes their reasons can be mysterious to us if we don't pay attention! Watch out for the head, they are usually head shy, don't grab too tightly and suddenly, to the snake it feels almost like being bitten by an animal, don't mess with them too much while they are grumpy and shedding, and don't go hold them if you've been playing with mice, you'll smell like food! It's all basically common sense.

I've never even been hissed at, or struck at. Nathan was hissed at when we first got her, but she had tics that we had to deal with, so it was a stressful situation. Since then she's been a doll!